The Joy of a Japanese Screwdriver

lbcgav said:
Would this information help us in finding the ever-elusive screws for Sansuis?
Click to expand...
I'm working on it. Stay tuned.

Tia said:
I have 2 mangled screw heads in my Pioneer CT-F9191 from using non-JIS screwdrivers (or maybe I'm just a hack). Was about to pull the trigger on this set, but wasn't sure the sizes in this set would be sufficient. The set has sizes #00, #0 and #1. Any screw driver size experts here that wouldn't mind chiming in? Will all three cover it or do I need just one size?

From the ad-
Megadora #900 Series JIS Drivers with comfort grip handle. Sizes include: #00, #0 and #1 which are commonly used in Japanese RC equipment. Larger handle, designed for maximum dexterity. You can't go wrong with this set.
Click to expand...

#2 is by far the most common size. Another interesting difference between JIS and DIN/ISO is cross point drive size. JIS specifies #2 for smaller diameter screws than DIN/ISO. The screws used in Sansui equipment are mostly 3mm diameter. DIN/ISO would require a #1 drive for these screws but JIS specs #2.

#00 and #0 are smaller than #1. Unless you are working with really tiny JIS screws, #2 covers almost everything. If you feel a need, get a #1 but unless you are working on watches or eye glasses no need for anything smaller.

- Pete
 
Yes this is correct, in another life I was a Toyota Mechanic, so I was aware of this, and have the appropriate drivers from when I was a mechanic.
Japanese cars are full of them as well, but just to be difficult, they have both types....
 
There are literally scores of different screw heads. At some point I saw a really fascinating website that showed them all but I've forgotten where that was.
 
We need more companies like Stihl. They are great maintaining consistency on their products and even supply a multi-tool with their chainsaws. It's pretty darn handy to adjust chainsaw tension, replace bar and chain, and remove the spark plug with one tool :thumbsup:
 
LBPete said:
So if you are in the mood for more JIS trivia, here's another little nugget. Industrial standards like JIS do a whole lot more than just determine screwdrivers. They set things like thread pitches and bolt head sizes. Japanese cars are built to JIS standards and the common bolt head sizes are 10, 12 and 14mm. European cars are built to ISO/DIN standards and the common bolt heads are 11, 13 and 15mm. US auto manufactures are switching over to DIN standards.

- Pete
Click to expand...
Right.. and like the half inch before, if you work on Japanese cars it's always the 10 that's missing from the socket/wrench set.. being most often used it gets lost or misplaced. Keep several around.
 
I can't resist adding a historical note to this thread!

What became known as Phillips screws were actually invented by John Thompson in 1932, but Thompson was unsuccessful at marketing the idea and sold his invention to Henry Phillips. Phillips was successful at promoting the Phillips-head fastener. General Motors was one of the first customers; Cadillac was first to adopt it in 1936. Phillips became the American industry machine-screw standard.

The first socket-style fastener practical for mass production usage was the Robertson screw, designed by Canadian Peter Robertson and patented in 1908. A socket-style driver will not slip out of a screw head like a slotted blade driver during use. For a few years, the Robertson screw was a North American standard; Ford Motor Company (one of Robertson's first customers) used Robertson screws on the Model T assembly line, where this simple socket-style fastener saved about two hours labour per car. Henry Ford attempted to acquire exclusive licensing rights to produce and market Robertson screws in the USA. Robertson turned Ford down. We can surmise that Ford was stuck purchasing Robertson screws from their Canadian manufacturer, and that didn’t go down well.

Henry Ford later turned to Henry Phillips, whose cross-style socket screw fasteners accomplished much the same benefits on the production line, probably at lower cost than Robertson.

To this day, Phillips fasteners are ubiquitous in the USA and Robertson fasteners are much more common in Canada than Phillips. Robertson fasteners and drivers are specialty items in the USA and not commonly available there.

Some believe that the Phillips screw socket was designed to cam out, and it does “cam out” at lower torque levels than other socket-style fasteners, but there is nothing in the original patents describing this as a design feature. Later patents for a refined Phillips head do mention the “cam-out” feature.

JIS fasteners offer the same assembly advantages as Phillips fasteners, but are designed so that a JIS driver won’t “cam out”. A Phillips driver will damage a JIS screw head and cam out, ruining the JIS fastener’s head. Lots of Japanese-manufactured goods like audio gear and cameras to name the most common that we are familiar with, are put together with JIS fasteners.
 
LBPete said:
So if you are in the mood for more JIS trivia, here's another little nugget. Industrial standards like JIS do a whole lot more than just determine screwdrivers. They set things like thread pitches and bolt head sizes. Japanese cars are built to JIS standards and the common bolt head sizes are 10, 12 and 14mm. European cars are built to ISO/DIN standards and the common bolt heads are 11, 13 and 15mm. US auto manufactures are switching over to DIN standards.

- Pete
Click to expand...

It gets worse.

DIN and ISO are not the same thing. DIN was the older German standard; ISO is what everyone is moving to. So basically if you work on both Eurocars and Japanese you need all the sizes by 1mm pretty much, although by the table it looks like your 9, 15, 20, and 23mm might not ever get used unless you have a really funky oddball fastener (or you work on rusty old crap and need to find a socket that just fits a rust damaged and now undersize bolt head).

https://www.boltdepot.com/fastener-information/bolts/metric-bolt-head-size.aspx

So for an older VW, say, you would need for most jobs, 10, 13, 17, 19, 22 (the only use I can think of off the top of my head for a M7 machine screw, which had a 11mm head, was the lower ball joint to control arm bolts on an A1 chassis VW... Originals were riveted on, but if you replaced them, the holes needed a M7. Why do I still remember this?)

But now today, it is 10, 13, 16, 18, 21... looks like the spec for M7 is not in the ISO table I posted, not sure if it is incomplete or they just discourage use of that size. I do know that I was incredulous working on my newish (now 10 years old) BMW and questioning if I really needed a 16mm wrench because I didn't remember ever using it before...
 
In a pinch, I have found that the corner edge of a P-38 can be used for a whole lot of screws.

P-38_Can_Opener.jpg
 
BLAH BLAH said:
What is a p-38!?!
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Before the US armed forces came up with Meals Ready to Eat (MREs), readily available food in the field came in the form of C-Rations, food in cans. Most of it was not bad, except for the horrendous Ham and Lima Beans. A case of C-Rats came with I think four of the little P-38s inside brown paper. It was a can opener. Stick the point into the edge of the top and open the can with a quick back and forth motion, rotating the can with the other hand as you went. With practice it could be done as quickly as the Swiss Army Knife can opener blade and it did not leave all those sharp points. That blade thing folds flat BTW.

This little doohickey is useful for all sorts of things, a last resort screwdriver, an easy way of cutting through packing tape (with pressure on the point of the edge, not the blade), cutting rope (slowly, with the blade), a general purpose wedge, a string cutter or wire stripper (the little indent by the blade and more. I have had one of these on my keychain for 50 years now and have used it many many times. I have never heard of one breaking or wearing out.

I rank the P-38 with duct tape and WD-40 as the most useful things to have around for unexpected little jobs.
 
Imprecise said:
Before the US armed forces came up with Meals Ready to Eat (MREs), readily available food in the field came in the form of C-Rations, food in cans. Most of it was not bad, except for the horrendous Ham and Lima Beans. A case of C-Rats came with I think four of the little P-38s inside brown paper. It was a can opener. Stick the point into the edge of the top and open the can with a quick back and forth motion, rotating the can with the other hand as you went. With practice it could be done as quickly as the Swiss Army Knife can opener blade and it did not leave all those sharp points. That blade thing folds flat BTW.

This little doohickey is useful for all sorts of things, a last resort screwdriver, an easy way of cutting through packing tape (with pressure on the point of the edge, not the blade), cutting rope (slowly, with the blade), a general purpose wedge, a string cutter or wire stripper (the little indent by the blade and more. I have had one of these on my keychain for 50 years now and have used it many many times. I have never heard of one breaking or wearing out.

I rank the P-38 with duct tape and WD-40 as the most useful things to have around for unexpected little jobs.
Click to expand...
Yep... I've seen 'em. I liked the pound cake.
 
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